Thermostat



N ov. Z9, 1927. 1,650,942

L. P. HYNEs ET AL THERMOSTAT Filed Jan. 8. 1926 nvewoT/.s H Lee PH nes and arr W jam 325% Via/i4 bkcmm'y l revealed new., aa lean E959@ i l parent LEE P. HYNES AND HARRY A. WILLIAMS, OF ALBANY, NEW YRK, SSEGNGRS'T@ HYNJES @L COX ELECTRIC CORPORATION, OF ALBANYNEW YORK, l. CORPRATEUN 0F NEW YURE.

THERMOSTAT.

Applicatibn led January 8, 1926. Serial No. 80,0%.

automatically bends as it becomes heated,

l metals and thus controls an electric circuit. We employ a narrow rectangular strip ot this type and -cont'ine it between two immovable endss'tops, and add a third stop on one side at or near the middle which may also serve as the electric contact. 'lhe end stops are so adjusted that at a given normal ternperature the strip'will press rmly against the side stop and thereby close the electric r circuit. As the strip begins to heat, its tirst 0 tendency is to arch as a'whole because ot the unequal expansion of the two metals,

thereby pressing more firmly against the side stop. Since the side stop is immovable, the two halves oi 'the strip thus begin to arch 3@ independently of each other as the tempera-v ture increases until the vtwo lines ot thrust `from the respective end-stops towards the center `pass the dead center relation to each other. Then the strip snaps away from the 35 side stop and breaks the circuit. -WVhen the temperature drops again the stripreturns to its initial position, also with a snap. l

Referring tothe drawingl represent-s a rigid base plate having' at its respective ends the two upright portions A and B. On the inside ot upright A is a horizontal lll-groove,-

and through upright B passes a screw 4 having a socket-like inner end and secured at.

screw 6. ln the bottom of the base is a 'screw 5 which Aserves as a backlstop for the'l strip and is locked by another set screw rlhe compound strip 3 shown in Fig. 3, is

right A. Between theA two shoulders is am due to unequal expansion of the component,

the desired point of 'adjustment by a set pointed projection, the tip end ol which is formed into a small cylindrical ball that is received 1n the end socket ot screw l. VNear the middle oit the strip is a rivet 9 (see Fig'.

' 4l)l insulated therefrom by mica washers 1'? and an insulating bushing l2. YlFhe lower end oit the rivet 9 is headed over against a bronze washer ll and on its upper end is a loose Contact disc 2% of silver. The slight play of this disc is limited by a 'flange on the washer below it and the headed end ot3 the rivet above it. Extendingn across the uprights A and B and seated thereon is a sheetmetal channel-shaped bar 2 (see Fig. 2) through the bottom olD which project two insulated contacts l0 that are engaged by the silver disc 8 and serve as an immovable side-stop 'tor the strip. The channel-bar 2 is secured at one'end to upright A by rivets 16 and at the other end is adjustablv secured to upright ld by ascrew Q0. The line wires 18 connect with the said contacts l0 respectively and pass out at one end oit the channel 2 under a clamp la f ln operation the set of strip 3 is so adjusted that at normal temperature', the disc 8 will bear against contacts l0 with Sulli- Acient force to close the circuit from one.

contact to the other, thesilver disc' 8 bridgingr the gap between them; The contacts l0 also serve to stop any upward movement ot the strip at that point. Between contacts 10. and the two ends Aof the strip there is' no side stop so that each half ot the" strip can arch independently as it will. {t a definite higher point ot temperature the direction of the counterthrust from the' respective ends ot the strip towards the center will become such that the-strip will spring awayV from contacts l0 and against backstop 5 thereby opening the circuit.

What we claim as new and desire to secure im Aby Letters Patent is:

. 1. A lthermostat comprising a heat-respon# sive strip with xed end lstops therefor and' va distorting side stop tor producing local` lateral movement of the strip termined' temperature.

2. A thermostat comprising a heat-respon sive metallic strip, with fixed end stops and at a predel V a distorting side stop therefor at an intermediate point of the strip local lateral movement of t determined temperature.

3. A thermostat com rising a heat-responsive metallic strip, la vase having two end stops for the strip one having a lmife'ed e engagement with the stri and an interme iate distorting side stop ihr producing local lateral movement of the strip t a predetermined temperature.

4., A thermostat comprising a base having offset stops, a heat-responsive metallic strip held under stress between said stops, a side stop. at an intermediate point of said strip in position to limit the lateral movement ot' the strip at that point leaving the strips free to respond locally between the side-stop for producing e strip at a preand the two end stops and an electric circuitv controlled by' lateral movement of the strip. 20

the said base,a bridging member extending between said stops, and a side stop for the stri mounted on said member at an interme iate point thereof.

6. A metal thermostat comprising a base, a parallel heat-responsive stri having endstops on said base, a channel-s ape bridging member extending between said stops, a side stop for the strip serving also as an electric circuit-closer, and circuit Wires in said channel.

LEE P. HYNES. HARRY A. WILLIAMS. 

